1. Technical Field of the Invention
The present invention relates to vehicles for lifting and transporting containers.
More particularly, the present invention relates to vehicles, also known as haulers, having a novel and substantially L-shaped boom and lift assembly which is attached to a vehicle, in which a tilt plate and a fork frame are operable for both lifting and safely positioning a container on the flat bed portion of the vehicle.
Alternatively, the specially constructed boom and lift assembly is able to utilize a hook lift and hook for loading and unloading containers from the flat bed of a truck.
Irrespective of whether the tilt and fork frames or the hook lift and hook are used for a particular container, the lifting assembly of the invention allows for loading and unloading to directly take place from the rearward end of the truck, thereby avoiding loading and unloading from either the left- or right-hand sides of the truck, or other vehicle, thereby avoiding the inherent safety hazards which are attendant side vehicle loading.
The vehicle of the present invention is also designed to have a lower center of gravity for greater stability than comparable loading trucks currently known to the art.
2. Description of the Prior Art
Containers, such as Dumpsters, have become widely used for containing trash or carrying other articles. Trucks having a front-end, or side-end loader-type mechanism are often used to follow a route on a regular basis, stopping at each container to collect the contents therein.
Due, in part, to the high cost of trucks having a front end, or side, loader-type mechanism, many collectors have resorted to using smaller, lower costing vehicles which have a rear-mounted-type mechanism for transporting fully loaded containers. Such vehicles, however, having a rear-mounted-type mechanism are designed to carry empty containers from one location to another, because transporting fully loaded containers creates a safety hazard. Specifically, a fully loaded container would extend and overhang the rear wheels of the vehicle and raises the center of gravity of the entire vehicle, thereby reducing the weight distribution on the front wheels and thereby resulting in a decrease in the ability to steer the truck.
Mechanisms for loading and transporting a container on a bed of a vehicle, so that it does not overhang the rear end thereof, including Tufenkian et al., U.S. Pat. No. 4,778,327, and Bohata, U.S. Pat. No. 4,943,203.
Tufenkian et al., U.S. Pat. No. 4,778,327, discloses a container lifting mechanism, which is mounted on a fixed flat bed of a vehicle. The lifting mechanism includes a track extending along the length of the bed, a tray which can be moved along the length of the track, and a jack-up assembly (fork lift) attached to, and supported by, the tray. A pair of hydraulic cylinders, attached between the tray and the jack-up assembly, permit forward tilting of the jack-up assembly toward the vehicle cab. In use, the tray carrying the jack-up assembly is moved to the rear of the vehicle. The fork is lowered below the bed and the vehicle is backed towards a container until the fork engages sleeves in the container. The fork is then raised, lifting the container above the bed. The tray is moved by a hydraulic ram toward the truck cab and the jack-up assembly is tilted toward the cab.
Bohata, U.S. Pat. No. 4,943,203, discloses a vehicle mounted container lifting mechanism with the added ability to tilt the bed about 30xc2x0 by pivotally attaching the bed to the chassis above the rear wheel of the vehicle for the purpose of enabling the lifting fork to be brought closer to the ground.
Carlson, U.S. Pat. No. 3,971,486, discloses a vehicle for transporting roller-type containers, in which a fork lift device is attached to a frame that is pivoted between a vertical position and a position coplanar with the chassis of the vehicle, using multiple lifting means.
Although suitable for their intended uses, the above-identified prior art references are costly and have limited capability for lifting fully loaded containers. Specifically, these devices provide separate means for (1) lifting containers; and (2) positioning the container on the truck bed.
There is a need for a low-cost vehicle for lifting and safely transporting fully loaded containers, which provides the safety of rearward loading and unloading, while maintaining the overall stability and versatility of the vehicle during the loading and unloading procedure.
It is, therefore, an object of the present invention to provide a vehicle for transporting containers, which may be loaded and unloaded from the rearward end of the vehicle, in which the vehicle is low cost, reliable and operable for lifting and safely transporting fully loaded containers on the vehicle.
It is a further object of the present invention to provide a vehicle for transporting containers, in which the vehicle is provided with a lower center of gravity for greater stability during rearward loading and loading of containers.
It is, still, another object of the present invention to provide a vehicle for lifting and transporting containers, in which the vehicle enables a fully loaded container to be positioned generally between the front and rear wheels thereof utilizing either a hook lift and hook or a tilt plate and fork frame device.
The foregoing and related objects are achieved by the present invention in which a hauler, e.g., flat-bed truck or similar vehicle, is provided with a base assembly and a lift assembly, with the lift assembly preferably comprising either a hook lift and hook, a tilt plate and fork frame apparatus, or both the hook and fork frame apparatus. Both the hook and fork frame means of the invention would be capable of engaging a container, located rearward of the vehicle, in a complementary manner for allowing the container to be loaded onto the vehicle. The present invention further includes a substantially L-shaped boom assembly, which is pivotally attached to a pair of lift plates, which in turn are attached to the left- and right-sides of the base assembly of the vehicle. The boom assembly is arranged (when not loading or unloading a container or the contents thereof) substantially adjacent the passenger cabin of the truck or similar vehicle in order to provide greater stability by virtue of a lowered center of gravity.
The base assembly, preferably, comprises a frame for supporting a container in its loaded position, as well as for supporting the lift assembly of the invention.
The distal end of the base assembly, substantially above the rear fender of the vehicle and opposite the end of the base assembly from that end which is adjacent the passenger compartment, preferably includes, for example, a pair of rollers held in a movable arrangement by respective ear hinges, for allowing a container to be loaded onto, or off of, the base assembly from the rear end of the truck.
The substantially L-shaped boom is constructed with two main segments, each of said main segments having one portion which is upright and substantially adjacent to, and parallel with, the outer, rear surface of the passenger compartment of the vehicle prior to any movement of the boom and lift for loading or unloading of a container or its contents. A lower portion of each segment of the boom is preferably arranged at a slightly obtuse angle (e.g., an angle of greater than 90xc2x0 to approximately 140xc2x0, most preferably, 103.5xc2x0), vis-a-vis, the upright portion of each segment. The lower portion of a given segment of the boom assembly extends below, and outside of the base assembly and is pivotally connected with lift plates of the lifting mechanism located on the left- and right-hand sides of the base assembly.
For unloading a container having complementary hook engagement means from the rear end of the vehicle, a hook lift portion of the lift assembly is pivotable for engagement of the hook portion thereof (e.g., an ear hook) with an eyelet, ring, or hook bar of a container. Once, for example, the hook of the invention is engaged with the container, the hook lift of the lift assembly is pivoted in an upwards direction, thereby tilting the container so that a bottom portion of the container, or a multi-body loading element, is able to rest against the pair of rollers located at the rear end of the base assembly. From there, the substantially L-shaped boom assembly is able to be slowly pivoted in a rearward direction from a position adjacent the passenger compartment of the vehicle toward, the rear end of the vehicle. At the same time, the hook lift is able to be lowered so that rollers, or other means for movement, located, or placeable, at the bottom of the container may safely contact the ground rearward of the vehicle and place, at rest, the container behind the vehicle.
In an alternative arrangement for unloading a container from the flatbed portion of the vehicle, the lift assembly includes a fork frame pivotally attached to an inner swing arm of the lift assembly, which, in turn, is pivotally attached to the boom, with a fork frame being attached to a tilt plate for engaging a container. Means for maintaining the tilt plate in a substantially vertical orientation during an unloading procedure and means for pivoting the tilt plate between a substantially horizontal transporting position and a substantially vertical lifting position are included.
For a loading procedure, as opposed to unloading a container from the flatbed portion of a truck, or other vehicle, the foregoing steps would be carried out in reverse order.
In a further preferred embodiment of the present invention, a rotator is provided for the tilt plate and folk frame assembly for allowing the lift assembly to rotate in a continuous 360xc2x0-manner for dumping the contents of a container.
In a particularly preferred aspect of the present invention, the lifting folks of the folk frame are horizontally foldable when their use is not required. Such folding of the lifting folks may either be carried out manually or by electrical, or other mechanical, means.